One of the most exciting technologies available today, wireless networks are being implemented by organisations of all sizes and verticals to improve productivity and decrease costs.
In this first article of a two-part series, I will describe some recent standards affecting WLAN technologies and discuss the standard components of a typical WLAN solution. Additionally, I will address the issue of security on a WLAN. My next article will take a detailed look at WLAN benefits and offer a cost comparison between a wired and wireless LAN.
Understanding the different flavours of 802.11
To know where we are with WLAN solutions, we need to take a quick look at how the technology has evolved. By now, most of us have heard of the 802.11 WLAN standards established by the Institute of Electrical and Electronic Engineering (IEEE). Before 802.11, all radio-frequency wireless network communications was proprietary. 802.11 established the standards for WLANs that vendors and manufacturers follow to ensure interoperability. Entire books have been written in an attempt to clarify the various specifications and differencing between the 802.11 protocol families. Table A briefly outlines the differences among the four.
Less confused? I didn't think so. It takes a lot more reading and research to fully understand not only the differences but also the pros and cons of each standard. The main thing to know is that the current de facto standard being adopted by most vendors and organisations is 802.11b. The next few months will more than likely reveal the slow adoption of 802.11g products based on its higher transfer rate and compatibility with existing 802.11b specifications.
WLAN components and topologies
Now, let's take a look at the typical components that make up a basic WLAN solution. It's important to remember that wireless local area networks are just thatââ,¬"local. They are used within a single building or in a campus area building-to-building connection. WLANs are most often used on mobile systems as an extension to a wired LAN, as illustrated in Figure A.
Example of a standard wireless LAN topology
You need to be familiar with three types of WLAN components:
- Wireless network cards
- Wireless access points
- Wireless bridges
Most wireless network cards will connect to an access point. An access point is essentially a hub that gives wireless clients the ability to attach to the wired LAN backbone. The use of more than one access point in a given area is facilitated by the use of cell structures, which are similar to what mobile phone providers use to maintain your coverage area.
Thanks for your article, it cleared up some of the questions I had and was very informative.